Electronic transducer employing radioactive substances



1963 YOSHIRO NAKAMATSU 3,

ELECTRONIC TRANSDUCER EMPLOYING RADIOACTIVE SUBSTANCES Filed Nov. 18, 1958 I50 TOPE I50 TOPE OUT UT DEV/6E United States Patent Ofifice g 01 2, 122:

3,106,657 ELECTRONIC TRANSDUCER EMPLOYING RADIOACTIVE SUBSTANCES Yoshiro Nalramatsu, 2-62 Shimouma-cho, Setagaya-lru, Tokyo, Japan Filed Nov. 18, 1958, Ser. No. 774,730 Claims priority, application Japan Nov. 19, 1957 3 laims. (Cl. 313-54) The present invention relates to electronic apparatus employing radioactive substances such as radio-isotopes.

It is an object of the present invention to provide improved electronic apparatus wherein radioactive materials are employed as emitters.

it is a further object of the invention to provide improved television apparatus.

Briefly, to achieve its objectives the invention contemplates the provision of a television tube employing a radioactive emitter and thereby avoiding the need for power supplies for emission purposes, this savings facilitating the manufacture of portable television equipment.

Features and advantages of the invention will be made clear in the following explanation which is made with reference to the accompanying drawings in which:

FIG. 1 is a cross sectional View of one of the embodiments of a Braun tube apparatus according to the present invention;

FIG. 2 is a diagrammatic perspective view of a device for transmitting ,G-rays to a photoelectric fluorescent screen;

FIG. 3 is a cross sectional side view of an apparatus similar to FIG. 1 but provided with a device for the removal of rays;

FIGS. 4a and 4b illustrate a perspective view and a cross-sectional view of a device for amplifying detected waves according to the invention;

FIGS. 5a and 5b 'are a perspective view and a crosssectional view similar to those of FIG. 4 but of a modification; and

FIG. 6 is a cross sectional view illustrating a television camera apparatus according to this invention.

In FIG. 1, the illustrated apparatus consists of a display tube having a cathode container 1 in which a radioisotope 2 is accommodated. This container 1 is made of a material which efiectively shields rays emitted from the isotope, for example, lead, but has a hole 1' in the front surface through which rays are allowed to proceed when a cover 3 slidably provided to cover said hole is removed by the operation of a knob 4 and thus it serves as a cathode emitting B-rays. For the isotope 2, any isotope which emits fi-rays and is readily available can be used.

fi-Rays emitted from the isotope are controlled by a grid 5 which receives the information to be displayed and a horizontal and vertical control electrode 6 and proceed to a fluorescent screen 7 to form an image on the surface of said fluorescent screen 7.

FIG. 2 diagrammatically illustrates a flat device for deflecting ,B-rays emitted from an isotope in a container 1:: in order to project the ,B-rays to a desired spot on a fluorescent screen 7a. The S-rays are deflected to take a tortuous passage in the flat body as illustrated by the chain line.

FIG. 3 illustrates an apparatus provided with a device for the removal of 'y-rays when an isotope such as St is used which emits 'y-rays together with ,B-rays. In this device, ,B-rays and -rays are emitted from the container 1b via opening l'b in an inclined direction in relation to the fluorescent screen 7b, but the ,e-rays are deflected by a magnet 8b so that they proceed to the fluorescent screen 71) while the 'y-rays take a diiierent course. As well known in the art, -rays are not deflected by a magnetic field and hence the ,B-rays are separated from the 'y-rays by the action of the magnet 8b. This embodiment is further provided with a cover 3!) and grids 5b.

FIGS. 4a and 4b illustrate an embodiment which is used as a detected wave amplifier. A container 10 of an isotope is removably accommodated in a circular vessel consisting of two layers 9c and Mic. The layer 90 surrounds the container 10 and serves as a grid and element serves as an anode. The assembly of the elements 10, 9c and 10c is provided with legs 11c and may be connected to various outside devices. A signal is introduced to the grid 90 through a wire G by means of one of the legs which is connected to said wire G. Under the influence of the input signal, the quantity of fi-rays emitted from the isotope is controlled and an amplified output is taken from anode 10c and is transmitted to a suitable output device (not shown) through a wire P which is connected to another of the legs 1-10.

FIGS. 5:: and 5b illustrate a similar device but this device has a flat rectangular shape instead of a cylindrical form. In this embodiment, the container la is fiat and rectangular and is enveloped in a thin and rectangular grid 9d and, over the assembly of the isotope container 1d and the grid gd, a plate 10d is laid as shown in the drawing. The input signal introduced to a grid 9d is amplified and is transmitted to another suitable device through a line P similar to the arrangement in the apparatus of FIGS 4a and 4b.

FIG. 6 is a sectional view illustrating an isotope container 12 used as a cathode in a television camera tube. /iRays emitted from the isotope la in a container 1e are passed through a target 12, and a grid 13 is interposed between this target and a photoelectric screen 14 (which receives the image to be scanned) a control field being formed by electric coils 15 and electrodes 16- arranged as diagrammatically illustrated in FIG. 6.

This camera tube works generally in the manner of a conventional image orthicon. The rays emitted by container or source 1 are focused by coils 15. Screen 14 converts a visible image into transmitted electrons which pass to target 12 under the influence of electrodes 16 and grid 13 so that, due to secondary emission an electrostatic image is formed on target 12 which when scanned by the focused ray emits an electron collected by anode A coupled to output device 0. e

As explained above, the apparatus according to the present invention has various advantages, among which the following may be particularly mentioned:

( 1) The apparatus is light, compact and strong;

(2) The apparatus does not need an electric source for the emission of electrons;

(3) The apparatus is less expensive but forming with excellent results.

capable of per- Apparatus of the invention will provide an inexpensive light and compact portable TV unit which is easy to handle with no fear of damage. This invention is believed, therefore, to be a significant valuable invention which has a very wide field in use.

What is claimed is:

1. Apparatus comprising a target responsive to beta rays for transducin'g electronic and visual signals, a source of beta rays operatively disposed with respect to said target for directing said rays thereat, first means operatively associated with said source to cause said rays to scan said target, and second means operatively associated with said source for transducing the intensity of said rays and visually perceptible information on said target such that said intensity and information are correlated to said electronic signals. 1

2. Apparatus as claimed in claim 1 wherein said second References Cite-:1 in the file of this patent UNITED STATES PATENTS 2,032,545 McElrath Mar. 3, 1936 2,642,546 Patla June 16, 1953 2,810,850 Linder Oct. 22, 1957 2,849,621 Clark Aug. 26, 1958 OTHER REFERENCES Pocket Encyclopedia of Atomic Energy, Frank Gaynor, Philosophical Library, Inc., New York, N.Y., 1950. 

1. APPARATUS COMPRISING A TARGET RESPONSIVE TO BETA RAYS FOR TRANSDUCING ELECTRONIC AND VISUAL SIGNALS, A SOURCE OF BETA RAYS OPERATIVELY DISPOSED WITH RESPECT TO SAID TARGET FOR DIRECTING SAID RAYS THEREAT, FIRST MEANS OPERATIVELY ASSOCIATED WITH SAID SOURCE TO CAUSE SAID RAYS TO SCAN SAID TARGET, AND SECOND MEANS OPERATIVELY ASSOCIATED WITH SAID SOURCE FOR TRANSDUCING THE INTENSITY OF SAID RAYS AND VISUALLY PERCEPTIBLE INFORMATION ON SAID TARGET SUCH THAT SAID INTENSITY AND INFORMATION ARE CORRELATED TO SAID ELECTRONIC SIGNALS. 